Unary OR in the CPP14 grammar does not exist in the standard

[OmerSakar]

The CPP14 grammar file (liked below) describes 7 unary operators, of which the OR operator is one of them. The CPP14 standard does not describe such an operator nor is the operator described elsewhere.

https://github.com/antlr/grammars-v4/blob/30358d009ccd62ecfd3de4b81924b96807a93465/cpp/CPP14Parser.g4#L124

I believe this is a mistake since the standard only describes 6 unary operators.